Unstacking elevator



Oct. 7, 1941. GQPMARSDEN ETAL 2,253,451

. UNS'VIACKING' ELEVATOR Filad March 10, 1939 a Sheets-Sheet 1 Mum/ruesG. P. MARSDEN ET AL 2,258,461

QUNSTACKING ELEVATOR 8 Sheets-Sheet 2 Filed March 10, 1939 //a //9 a: wm bl A M v2) .95 64 Oct. 7, 1941.

G. P. MARSDEN ET AL UNSTACKING' ELEVATOR Filed March 10, 1939 8Sheets-Sheet 3 E616 we Arman/1 Oct. 7, 1941. G. P. MARSDIEN ET ALUNSTAGK ING ELEVATOR Filed March 10, 1939 I s Sheets-Sheet 4 AVA-M7026650265 2/1/4605 FEED STEELE? Oct. 7, 1941. G. P. MARSDEN ET AL 2,258,451

UNSTACKING ELEVATOR Filed March 10, 1939 8 Sheets-Sheet 5 m z/vmes:660F622 mesam F660 7554.52

Oct. 7, 1941.

G. P. MARSDEN ET AL UNSTACKING ELEVATOR Filed March 10, 1959 8Sheets-Sheet 6 1941. G. P. MARSDEN ET AL 2,258,461

UNSTACKING ELEVATOR Filed March 10, 1939 8 "Sheets-Sheet 7 25 AMA/mas:

GZUFGE Q M4PS'DE/V FEED 5 Oct. 7, 1941. G. Pf MARSDEN ET AL 2,258,461

UNSTACKING ELEVATOR Filed March 10, 1939 a Sheet s-Sheet a El I 5 TARTSTOP lA/Vf/VWES GZUFGE P M42505 F650 5m E i 1 Patented Oct 7,1941

UNSTACKING ELEVATOR George P. Marsden and Fred Stebler, Riverside,

CaliL, assignors to Food Machinery Corporation, San Jose, Calif., acorporation of Delaware Application March 10, 1939, Serial No. 261,018

28 Claims.

This invention relates to machines for handling receptacles and moreparticularly to machines for unstacking stacks of boxes. Although usefulin other industries, the present invention is shown and described inrelation to the citrus industry.

In this industry, oranges are brought from the groves to the packinghouses in field boxes, the latter being stored in stacks untilconvenient to run the fruit contained in these boxes through theprocesses of washing, grading, packing and otherwise preparing the fruitfor market. The practice in handling lemons on the otherhand, is to pickthe fruit when partially green and after washing and sorting the fruitas to color, the green fruit is placed loose in shipping boxes which arestored in stacks for as much as four to eight weeks until the fruitripens sufiiciently for marketing. The stacks of boxes containing suchfruit are usually stored in the packing house basement where it is cooland the boxes are elevated to the main floor of the building when thetime comes to prepare the fruit for shipment.

Of the several methods employed for elevating full boxes of fruit fromthe basement to the main floor, the present invention relates to themethod of elevating an entire stack and discharging the boxes, one at atime, from the top of the stack onto a horizontal'conveyor prior todumping the fruit from the boxes. In this method of unstacking boxes,the latter are retained in upright position during the unstackingprocess and are dumped manually or by a box dumping machine after beingunstacked.

A common principle employed in machines used heretofore for unstackingstacks of boxes is to elevate the stack and slide each successiveuppermost box from the top of the stack and discharge the boxes,individually, onto a horizontal conveyor. This practice often results ininjury to the fruit and the boxes or jamming of the machine whenprojecting nails and other irregularities of the boxes interfere withthe sliding of one box on .top of another.

Other types of machines designed for unstacking and dumping stacks offilled boxes employ a mechanism for clamping the box by pressinginwardly against its ends with sufficient pressure to enable suchmechanism to lift each loaded box from top of a stack and deposit thebox on a separate box conveyor. Fruit boxes are usually constructed bynailing side and bottom shook to side and bottom edges of the heads andmachines which employ this principle of pressing inwardly against thebox heads impose considerable strain on the nails holding the sides andbottom to the box heads and repeated strains of this nature tend toloosen the nails and eventually destroy the box.

It is an object of the present invention to provide a machine forunstacking stacks of loaded boxes in which each successive uppermost boxof a rising stack is lifted vertically free from the box thereunderprior to lateral shifting of the box out of the path of said risingstack.

Another object of this invention is the provision of such a box liftingmechanism which operates by clamping a box on the sides rather than theends thereof in a manner to prevent injury to the box.

A further object of this invention is the provision of a box unstackingmechanism adapted to retain a box in upright position during the liftingof said box from the top of, a rising stack and the shifting of said boxout of the path of said rising stack.

Still another object of the invention is to prevent the breakage ofboxes, etc., due to a stack being elevated with the boxes thereof inmisalignment.

Yet another object of this invention is the provision of such a machinein which the boxes of a stack being fed thereto on a floor conveyor arealigned transversely of the direction of travel of said stack prior toengagement of said stack by the stack elevator.

The preferred manner of accomplishing the foregoing objects as well asfurther objects and advantages will be made apparent in the followingdescription taken in connection with the accompanying drawings, inwhich:

Fig. 1 is a side elevational view of a preferred embodiment of theunstacker of this invention.

Fig. 2 is a plan view of the machine shown in Fig. 1.

Fig. 3 is a horizontal cross sectional view taken on the line 33 of Fig.1.

Fig. 4 is a horizontal sectional view taken on the line 4-4 of Fig. 1.

Fig. 5 is an enlarged, fragmentary, horizontal sectional view taken online 5-5 of Fig. 1.

Fig. 6 is an enlarged vertical sectional view taken on the line 6-6 ofFig. 1.

Fig. '7 is an enlarged horizontal sectional view taken on the line 'i--iof Fig. 6.

Fig. 8 is an enlarged sectional view taken on the line 8-3 of Fig. 3. r

Fig. 9 is a detail perspective view of the box gripping mechanism of themachine of the invenion.

Fig. 10 is a fragmentary, sectional view taken on the line I-I0 of F18.9.

Fig. 11 is a vertical sectional view through the entire machine taken onthe line II-Il of Fig. 2.

Fig. 12 is an enlarged fragmentary view of the upper portion of themachine of the invention and showing the operation thereof.

Figs. 13 and 14 are sectional views similar to Fig. 12 showingsuccessive portions of the mechanism during the operation thereof.

Fig. 15 is a horizontal sectional view similar to Fig. 3 illustratingthe operation of certain parts of the machine.

Fig. 16 is an electrical diagram showing the manner in which the machineof the invention is electrically controlled and operated.

Referring specifically to the drawings, an unstacker 10 comprising apreferred embodiment of this invention is shown in Fig. 1.

The machine I0 includes a frame II, a stack conveyor. I2, a stackelevator I3 and an unstacking conveyor I4 mounted on the upper end ofthe frame II.

The frame I I The frame II includes a pair of vertically disposedchannels 20 and 2|, the latter being shown in Fig. 3 and connecting thechannels 20 and 2| as shown in Figs. 6 and 11 are cross members 22 and23. Fixed to each of the channels 20 and 2i as shown in Figs. 1 and 3are horizontal angle irons 25, the latter supporting the channels 20 and2| over a suitable pit 26 provided in a floor 21. Fixed on upperextremities of the channels 20 and 2I are brackets 30 shown in Fig. 6upon which horizontal angle irons M are mounted.

Fixed on opposite ends of the angle irons 3| are vertically disposedpairs of angle iron members 32 and 33, the latter being joined at theirupper ends by horizontal angle irons 34 as shown in Figs. 1, 2 and 6.Attached to upper ends of the channels 20 and 2I is a pair of guideplates 31, these being fixed to lower extremities of the angle irons 32as shown in Fig. 1. Mounted on brackets 38 extending vfrom the angleirons 32 are bearings 39, the purpose of which will be made clearhereinafter.

The stack: conveyor I2 The stack conveyor I2 includes a transverse shaft45, the latter being Journalled in bearings 46 provided on the channels20 and 2| as shown in Fig. 3. Fixed on the shaft 45 is a pair ofsprockets 41, the latter being aligned with a pair of idle sprockets 41amounted in the floor 21 at the opposite end of the stack conveyor I2 asshown in Figs. -3 and 11. Trained about the sprockets 41 and the idlesprockets 41a are chains 48, upper flights of which are carried insuitable track 49 provided on the floor 21 as shown in Fig. 3. Fixed onone end of the shaft 45 as seen in Figs. 1 and 5, is a sprocket 50, thelatter being driven from a suitable motor I by a chain 52.

Provided on the floor 2'! on opposite sides of the stack conveyor I2 arebearings 55, the latter being aligned with the aforementioned bearings39 as shown in Fig. 1. Journalled in the bearings 39 and 55 are verticalshafts 60 and 6| each of which has a gate 62 thereon as shown in Figs. 1and 3. Mounted on the upper end of the shaft 60 as shown in Fig. 2 is alever 64 having arms 65 and 66 thereon and formed to provide a stop 61,the latter engaging the bracket 38. Fixed on the upper extremities ofthe shaft BI is a lever 68, the latter being connected to theaforementioned arm 66 of the lever 64 by'a diagonalcross link 69.Connected to the arm 66 of the lever 64 and the frame II is an extensionspring 10 for the purpose of maintaining the shafts and 6| in thepositions in which they are shown in Fig. 2. Mounted beneath the floor21 as shown in Figs. 3 and 11 is a switch 15 which is operated by alever 16 fixed on the lower end'of the shaft 6|. Journalled in upper andlower pairs of bearings 80 and 8| respectively, mounted on the channels20 and H are vertical drums 82 having shafts 83 as shown in Figs. 1, 2and 3. Fixed on'lower ends of the shafts 03 of the drums'82 are bevelgears 84, the latter meshing with bevel gears 85 which are fixed toshafts 06, these being Journalled in bearings 8Ia formed integrally withthe bearings 8| as seen in Fig. 5. The shafts 86 are driven from theconveyor shaft 45 by chains 81 trained about sprockets 88 on the shaft45 and sprockets 89 on the shafts 86.

Mounted adjacent the floor conveyor I2 as shown in Fig. 8 is a pair ofswitches 90 and 9|, the latter being provided for the purpose ofcontrolling the stack conveyor I2 in a manner to be describedhereinafter.

The stack elevator I3 Journalled in suitable bearings I00 provided onlower extremities of the channels 20 and 2| is a transverse shaft IOIhaving a pair of sprockets I 02 fixed thereon as shown in Figs. 4 and11. Journalled in bearings I05 on the brackets 30 at the upperextremities of the channels 20 and 2I, as shown in Fig. 6, is atransverse shaft I06, the latter having sprockets I0'I fixed thereonwhich are disposed in alignment with the sprockets I02 of the shaft IOI.Trained about the sprockets I02 and I01 are stack elevator chains I08guided by suitable tracks-I09 provided onthe channels 20 and 2| as shownin Figs. 3 and 4. As shown in Fig. 8, the chains I08 are provided withoversize rollers IIO to reduce friction between the chains and thetracks I09. Carried by the chains I08 as shown in Figs. 8 and 11 is apair of elevating baskets III, each of the latter including a platformII2 secured to brackets II3 fixed on the chains I08. For the purpose ofbracing the platforms II2, diagonal braces II4 are provided, the latterextending from the platforms II2 to suitable brackets II5, these beingalso attached to the chains I08. Extending transversely between thechains I08 and brackets II5 of the baskets III are spacer rods II6.Fixed on one extremity of the shaft I06v as shown in Fig. 6 is a smalland a large sprocket, H0 and H9 respectively and rotatable on the shaftI06 between the bearings I05 and sprockets I01 is a pair of frictionwheels I22, the latter having bushings I23. The wheels I22 are providedon their outer peripheries with treads I24 of suitable friction materialas shown in Fig. 6. Formed integral with each of the wheels I22'is asprocket I25, the purpose of which will be made clear hereinafter.Journalled in bearings I29 provided on channels 20 and 2I below theshaft I06 is a shaft I29 having a pair of small sprockets I30 fixedthereon, the latter being in vertical alignment with the sprockets I25of the wheels I22, the latter being driven from the shaft I29 bysuitable chains I3I trained about the sprockets I25 and I30. Fixed onthe extremities of the shaft I29 as shown in Fig. 6 are sprockets I33and I34. The sprocket I33 is in alignment with the aforementionedsprocket II9 of the shaft I06, the latter being driven by a chain I35trained about the sprockets opposite sides thereof.

I I9 and I33. Fixed on the shaft I29 between the sprocket I33 and theadjacent bearing I28 is a sprocket I36. Below the shaft I29 is a shaftI38 which is journalled in bearings I39 also provided on frame channels28 and 2|, the shaft I38 having a sprocket I48 and collar I4I fixedthereon. The shaft I38 is adapted to'drive the shaft I29 by means of achain I42 trained about the sprockets I48 and I38 as shown in Figs. 1and 6.

Mounted on one end of the shaft I38 adjacent the sprocket I48 is asafety sprocket I45, the latter including a hub I46 as shownin detail inFig. 7. Formed integral with the hub I46 is an annular flange I41, andyieldably mounted relative to the hub I46 is an annular plate I48, thelatter being secured against rotation in relation to the hub I46 bystuds I49, these being threaded into the plate I48 and extending throughsuitable holes provided in the hub I46. On each of these studs I49 is acompression spring I58, the latter being compressed by nuts I5I providedon the studs I49. Mounted between the flange I41 and the plate I48 is asprocket I53, the latter having rings I54 of brake lining materialprovided on The sprocket I53 drives the shaft I38 by frictionalengagement of theflange I41 and the plate I48 with the rings I54. Thenuts I5I are adjusted so that the sprocket I53 will drive the shaft I38during normal operation of the machine I8 and in the event of anemergency resulting from jamming of any of the mechanism of the machineI8, the safety sprocket I45 slips in relation to the hub I46 so as toprevent breakage of the machine.

The stack elevator I3 is driven by a motor I68 mounted on the floor I21,2. chain IBI extending from the motor I68 to the safety sprocket I85 asshown in Fig. 1. Provided at the lower end of the stack elevator I3 asshown in Fig. 8 is a pair of switches I65 and I66, the latter beingsupported by-a frame I61 extending horizontally between the channels 28and 2 I. switches I65 and I66 are provided for the purpose ofcontrolling the stack conveyor I2 and the stack elevator I3 in a mannerto be described hereinafter.

The boa: unstacking conveyor It The unstacking conveyor I4 shown inFigs. 1 and 2 includes a pair of aligned stub shafts I18 journalled inbearings I1I mounted on the under side of the angle iron frame members3|. Mounted on the inner ends of the stub shafts I 18 are idle sprocketsI12. Mounted on the vertical angle iron members 33 are bearings I14 inwhich stub shafts I15 are fixed, the latter having idle sprockets I16mounted thereon. Rotatably mounted in bearings I18 as shown in Fig. 2 onthe upper angle iron members 34 is a transverse shaft I19 having a pairof sprockets I88 fixed thereon. Fixed on one extremity of the shaft I19is an irregularly shaped gear II, the latter being formed to provide asemi-circular, concentric portion I82 as shown in Fig. 1 and aneliptical portion I83. Journalled in bearings I85 provided on themembers 34, is a transverse shaft I86, the latter having a sprocket I81on one end thereof and an irregular gear I88 on its opposite end. Thegear I88 has a semi-circular concentric portion I89 and an elipticalportion I98. The

- shaft I86 is driven from the aforedescribed shaft I29 by'a chain I92,trained about the sprockets I34 and I81 as shown in Figs. 2 and 6.Mounted in bearings I95 (see Figs. 1 and 2) provided on the angle ironframe members 32 is a transverse shaft I96 having sprockets I91 fixedthereon.

Below the bearings I are similar bearings 288 in which aligned stubshafts 28| are fixed, the latter having idle sprockets 282 rotatablymounted on the inner ends thereof. Trained about the sprockets I12, I16,I88, I91 and 282 are endless chains 285, the latter having a pluralityof equally spaced box-engaging members 286 extending transverselytherebetween.

As shown in Figs. 9 and 10, each of the box engaging members 286includes a transverse shaft 2 I8 pivotally mounted at its ends on pins2| I extending inwardly from the chains 285. Extending between thechains 285 adjacent to the shaft 2I8 is a rod 2I2. Fixed on the shaft2I8 adjacent each of the chains 285 is a pair of box-engaging shoes 2I5and 2I6. The shoe 2I5 includes a plate 2I8 having a corrugated face 2I9formed thereon. Integral with the plate 2I8 is a pair of bosses 228bored to receive the shaft 2I8, the latter being fixed to the shoe 2I5by a pin 22I. Formed integral with the plate 2I8 and extending below therod 2I2 is a stop finger 222. Coiled about the shaft 2I8 between thebosses 228 of the shoe 2I5 is a torsion spring 223. The shoe M6 issimilar to the shoe 2I5, having a plate 225 provided with a corrugatedface 226. Formed integral with the plate 225 is a pair of bosses 221bored to receive the shaft 2I8 and being fixed thereto by a pin 228.Formed integral with one of the bosses 221 is a stop finger 229extending above the rod 2 I2, and-provided on the shaft 2I8 between thebosses 221 is another torsion spring 238. The springs 223 and 23.8 ofthe shoes 2I5 and 2I6 respectively tend to urge the shoes into theposition in which they are shown in Fig. 9, with the finger 222 of theshoe 2I5 engaging the under side of the rod 2 I2 as shown. Mounted onthe angle iron frame members M, as shown in Figs. 2, 6, ll and 12 arehorizontal rods 235 to which a pair of spaced slide rails 236 are fixed,the latter serving to support the boxes discharged by the unstackingconveyor I4.

Mounted onand extending from the upper end of the frame II as shown inFigs. 1, 11 and 16 is an accumulator conveyor 231, the latter beingdriven by a chain 238 trained about the aforementioned sprocket II8 onthe stack elevator shaft I86 as shown in Fig. 1. Provided on theaccumulator 231 as diagrammatically shown in Fig. 16, is a box stop 239and tnree limit switches 248, MI and 242.

Operation of the machine I8 is controlled by an electrical apparatus 249shown in Fig. 16, the apparatus 249 including a controlcircuit 258 forthe stack conveyor I2 and a circuit 25I for controlling the stackelevator I3. The circuit 258, described in detail hereinafter,is'provided for the purpose of starting or stopping the stack conveyormotor 5| to cause the stack conveyor I2 to supply stacks of boxes to theelevator I3 as needed and in timed relation with the operation of theelevator I3. The circuit 25I serves to start or stop the stack elevatormotor I68 to enable the stack elevator I3 and the box unstackingconveyor I4 to deliver single boxes to the accumulator conveyor 231until the latter is full of boxes at which time the three switches 248,24I and 242 of the accumulator 231 are all opened so as to break thecircuit 25I andstop the elevator motor I68. The two circuits 258 and 25Iare inter-related but will be first described separately, the manner inwhich they are interrelated being pointed out later.

The stack conveyor control circuit 258' includes a three pole magneticswitch 255 having contact with the contacts a, b, and c by a magneticcoil.

268 having terminals'd and e. Connecting the contact b with the terminale of the coil 268 is a wire 26I and extending from the blades 269 totending from both or the arms :12 and m of the switches 3H) and 3I.I isa single wire I" which extendsto the blade 266b of the relay 296. Theaccumulator switches 248, 2 and the stack conveyor motor 5| are threewires 262.

Also included in the switch 255 is a circuit closer 263 adapted tobridge contacts a and b when ever the coil 268 is energized.

The magnetic switch 255 is controlled by a relay switch 265 havingcontacts I and g, blades 266a, 266b and a magnetic coil 261 providedwith terminals h and 7'. Positioned between the magnetic switch 255 andthe relay 265 is a three pole manually operated switch 218 havingcontacts k, m, n, and blades 21I, 212 and 213. Extending from thecontact 0 of the switch 255 to the contact m of the switch 218 is a wire214 and connecting the terminals 11 and e of the coil 268 and thecontacts and n of the switch 218 are wires 215 and 216 respectively.Joining the blades 21I and 212 of the switch 218 with the contacts jandg of the relay 265 are wires 211 and 288, the blade 213 being connectedto the terminal a of the coil 261 by a wire 28I. Connected to the blades21I and 212 of the switch 218 is a stack conveyor jog switch 282. Thefirst stack conveyor switch 98 includes an arm 283 which normallyengages a contact 0, the latter being connected to the contact J of therelay 265 by a wire 284. Extending from the arm 283 of the switch 98 tothe contact 1: of the circuit closer 263 is a wire 285. The second stackconveyor switch 9I has an arm 288, a pair of upper contacts p and p andlower contacts 1' and r, the contact r being connected by a wire 281 tothe terminal h of the coil 261 in the relay 265. The contact r of theswitch 9| is joined to both blades 266a and 26Gb of the relay 265 by awire 288. The switch I65 at the lower end of the stack elevator I 3includes an arm 298 and contact 8, the arm 298 being joined by a wire29I with the contact g of the relay 265 while the contact s is connectedby a wire 292 with the contact 1 of the second stack conveyor switch 9I.

The stack elevator control circuit 25I includes a three-pole magneticswitch 295 and a relay switch 296, these being similar to the switches255 and 265 of the circuit 258 and having the parts-thereof designatedby similar reference characters. Connecting the lead wire 256, 251 and258 with the contacts a, b and c of the switch 295 are wires 388,38I and382, respectively, and extending fromthe blades 259 of the switch 295 tothe stack elevator motor I68 are three wires 383. Connecting the contactb and terminal e of the coil 268 in the switch 295 is a 1 wire 384 andjoining the contact 0 of switch 295 with contact 9 of the relay 296 is awire 385. Extending from the terminal e of the coil 268 in the switch295 to the terminal 71. of the coil 261 of the relay 296 is a wire 386,and a wire 381 is provided to connect the terminal d in switch 295 withthe contact ,f of the relay 296.

Provided in the stack elevator control circuit 25I are start and stopswitches 3I8 and 3 respectively having arms 3I2 and 3I3 and contacts tand u. Extending from the contact u of the switch 3 is a wire 3I4, thelatter extending to the terminal a of the coil 261 of the relay 296. Thecontact t of switch 3I8 is connected to contact g of the relay 296 by awire 3I5 and ex- 242 include arms 328 and contacts 0, the latter beingconnected to a single wire 32I which extends to an arm322 of the switchI66 at the lower end of the elevator I3. Thearms 328 of the accumulatorswitches 248, 24! and 242 are connected by a wire 324. to the blade266!) of the relay 296. The am 322 of the switch I66 normally engages acontact w, the latter being Joined with the blade 266a of the relay 296by a wire 32 The aforementioned switch 15, positioned adjacent shaft 6|(see Figs. 3 and 8) is shown diagrammatically in Fig. 16 and includes acontact a: and a switch arm 338, the latter being normally urged intoengagement with the contact a: as shown. The contact a: is connected tothe upper contact 1) of the second stack conveyor switch 9| by a wire 33I.

The two circuits 258 and 25I are inter-connected by a pair of wires 333and 334, the former extending from the wire 325 to the arm 338 of switch15 and the latter extending from the wire 32I to the contact 9 of thesecond stack conveyor switch 9|.

Operation In practice, the unstacker I8 of this invention is preferablymounted on the floor 21 of a packing house basement as shown in Fig. 1with the upper end of the machine extending through the main floor (notshown) of the packing house where the fruit is prepared for marketing.After loading the stack conveyor I2 with stacks S of boxes B as shown inFig. 1, the truckman working in the basement closes the knife switch218. Closing of the switch 218 does not start the unstacker I 8 butsimply closes the necessary circuits to enable the unstacker to startwhen the operator on the main floor actuates the Start switch 3I8, theknife switch 218 being provided as a safety measure to enable thetruckman to prevent the unstacker I8 from being started when the latteris being serviced.

When the operator on the main floor is ready to have boxes of fruitdelivered by the unstacker I8 to the accumulator 231, he actuates theStart switch 3I8 which, through the relay 296 and magnetic switch 295,starts the elevator motor I68. The elevator I3 runs continuously duringnormal operation of the unstacker I8 and stops only whenthe accumulator231 is full of, boxes or whenv an interruption occurs in the delivery ofthe-stacks S to the elevator I3. I

The switches 328 areso arranged with relation to the accumulator 231that when the latter is filled with boxes all three 'of the switches aredepressed in open position. This breaks the circuit of the coil 268 ofthe switch 295 causing the latter to cut out and stop the elevator motorI68. Whenever a box over one of the switches 328 is then removed fromthe accumulator 231 the circuit of the coil 268 is re-establishedcausing the elevator and accumulator to be again set in motion.

The orderly and timely delivery of stacks of boxes to the elevator I3 bythe conveyor I2 is controlled by the switches 98, 9|, I65 and I66.

Before describing the manner in which the conwhich these switches willstart or stop the motors controlled thereby.

1. Closing the switch I65 momentarily by the passage of a rod II6 of theelevator past this switch will start the conveyor I2 only when theswitch BI is positioned as shown in Fig. 16, that is, when it is closedon the conveyor side, the switch 9I being in this condition when nostack is disposed on the conveyor I2 directly over this switch. In orderfor a stack to reach this position, it must be delivered by the conveyorI2 into the proper position to be elevated bythe elevator I3, that is,with the stack engaging the upright frame members 20 and 2I of, theelevator as shown in Fig. 15.

2. The opening of the switch I66, as when this is contacted by one ofthe rods III6 on the elevator it, will stop the elevator only when thestacks of boxes which have been placed on the conveyor I2 travel withthis conveyor towards the elevator I 3 until the foremost stack passesover the switch 90 and then over the switch 9| which is held indepressed position by said foremost stack then the latter is deliveredagainst the frame uprights 2|! and 2I in the proper position for beingelevated. The conveyor I2, of course, continues to operate after theforward motion of the first stack is thus halted by its de liveryagainst the frame members 20 and 2|, so

, that the next succeeding stack eventually travels switch M is open onthe elevator side, that is, 7

when this switch is not depressed so as to connect the terminals 1) andp. that when the switch 9I is disposed as shown in Fig. 16 and one ofthe bars II6 opens the switch I66, this will cause the operation of theelevator I3 and the accumulator conveyor 231 to be halted.

3. Assuming the conveyor I2 is in motion, it is to be noted that theopening of switch 90 as by the engagement therewith of the bottom box ofa stack travelling along on the moving conveyor I2 will not stop thisconveyor when the switch 9| is closed on the conveyor side as shown inFig. 16.

4. Opening the switch 9| on the conveyor side will not stop the conveyorI2 when the switch 90 is closed. Thus, when the initial stack,travelling on the conveyor I2 passes over the switch 90 and releasesthis so the latter is closed and then continues to be carried along theconveyor I2 until it passes over and depresses the switch 9| so-that thestack engages the frame members 20 and 2I which stop its forwardprogress, the conveyor I2 is not stopped but continues to travel, thechains of this conveyor slipping underneath the foremost stack, forwardmovement of which has thus been stopped.

5. Opening the switch 90, when switch 9| is open on the conveyor side,will stop the conveyor I2. This occurs when, after the first stack hasbeen delivered against the frame uprights 20 and 2| so as to ride overand depress the switch.

HI, 2. second stack carried by the conveyor I2 arrives in position whereit travels over the switch Sill and depresses this. As noted, this stopsthe conveyor I2.

6. In case the conveyor I2 should be halted as by the opening of theswitch 90 while the switch M is open, and, the switch 90 should then beclosed, as by the lifting of a stack therefrom, this will not start theconveyor I2 in motion and the only thing which will start the conveyornow is the momentary closing of the switch I65 or the actuation of thejog, 282. 7

As aforementioned, the stack elevator is started in motion by theactuation of the Start switch, 350. This does'not immediately start theconveyor I2, however, the latter remaining idle until one of the rodsII6 on the conveyor I3 engages the switch I65 and momentarily closesthis. This energizes the relay 265 which closes the magnetic switch 255and starts the conveyor l2 in motion. With the switches 90, 9!, M5 and566 functioning as heretofore described, it will be seen that when theconveyor i2 is started as by the momentary closing of the switch M5, the

Thus it is seen.

over and depresses switch 90 thus opening th latter and halting theconveyor.

If the delivery of the foremost stack over the switch 9| is delayed sothat this has not been accomplished at the time the rod II6 whichstarted the conveyor I2 by momentarily engaging switch I has passedaround to the point where this rod engages and opens the switch I66, theopening of the latter switch will halt the motion of the elevator I3.The conveyor I2, however, will continue in motion until its foremoststack is delivered into proper position for being elevated, where thisstack will depress the switch 9|, open this switch on the conveyor side,and close it on the elevator side, that is, by connecting terminals pand p. The effect of the 'latter action of switch 9| is to start theelevator I3 in motion again so that this elevator will lift the basketIII associatedwith the rod II6 aforementioned against the bottom of thestack posi-' tioned as aforesaid in readiness to be elevated and willelevate and separate the boxes of this stack in a manner to be pointedout hereinafter.

The stack elevator I3 is also stopped when a stack of misaligned boxesis delivered to the elevator I3, with one or more misaligned boxesholding the gates 62 open in the dotted line positions shown in Fig. 15.This holds the switch 15 (shown in Figs. 3, 11 and 16) open and causesthe elevator I 3 to stop when the switch I66 of the elevator I3 isactuated as aforesaid. When, after the elevator. has been thus stopped,such a stack of misaligned boxes is straightened to allow the gates 62to swing inward as indicated by solid lines in Fig. 15, switch I5 isclosed, the elevator I3 starts and the unstacker I0 resumes normaloperation.

When the stack conveyor I2 is operating, the vertical drums 82 aredrivenin the directions indicated by the arrows in Fig. 15 by theaforementioned chain 81 and bevel gears 84 and 85 shown in Figs. 3 and5, the peripheral speed of the drums 82 being equal to the rate oftravel of the stack conveyor chains 48. As shown in Fig. 15, the spacebetween the innermost surfaces of the drums 82 is substantially equal tothe length of the boxes 3 and any boxes out of alignment endwiserelative to the stack S will be moved into proper alignment as the stackpasses between the drums 82, the latter also serving to guide the stackduring its elevation by ,the elevator i3.

As shown in Fig. 12, the unstacking conveyor I4 is timed in relationwith the elevator I3 so that the uppermost box of a rising stack S isengaged by one of the box-engaging members 206 when the bottom of thisbox rises into approximate horizontal alignment with the shaft III6. Theunstacking conveyor I4 is driven through the irregularly shaped gearsI8I and I88 for the purpose of decreasing the speed of the conveyor I4at the time of engagement of the uppermost box B of a stack by thismember 206 and increasing the conveyor speed during discharge of the boxfrom the unstacker III. At the time a box is first engaged by thismember 206 and urged against the wheels I22 as shown in Fig. 12, theconveyor I4 is traveling at its slowest speed as the portion I90 of thedriving gear I88 having the smallest radius is meshing with the extendedportion I83 of the driven gear As the peripheral velocity of the wheelsI22 exceeds the lowest rate of travel of the conveyor I 4, the boxclamped between the wheels I22 and member 206 is lifted slightly fasteron the side engaging the wheels I22 as shown in Fig. 13. This mode ofoperation prevents the possibility of crushing a box between the wheelsI22 and the advancing member 206, particularly when the uppermost box isengaged before reaching the height at which it is shown in Fig. 12. Asstacks of field boxes vary as much as two inches in over-all height, theuppermost box is apt to be clamped between the wheels I22 and member 206when the bottom of this box is located variously from one inch below toone inch above the level of the center of the wheels I22.

When the unstacking conveyor ll moves from the position in which it isshown in Fig, 13 to that shown in Fig. 14, its speed increases to exceedthe peripheral speed of the wheels I22. This results in the box beingslid over the wheels I22 at a speed greater than the peripheral speed ofthe wheels. The force required to produce this sliding action increasesthe pressure of the member 206against the box sufficiently to preventthe rear side of the boxfrom tipping downward until the box is supportedby the rails 236. In this portion of their action the wheels I 22 may besaid to act as a skidway.

The unstacked boxes are successively pushed onto the accumulator 231 bythe unstacking con-- veyor I4 and should the accumulator become full ofboxes so as to depress all three of the switches 240, 2 and 242, theelevator I3 is automatically stopped as aforestated and is restartedwhen one or more of the accumulator switches is allowed to close byremoval of boxes therefrom. 1

The conveyor jog switch 282 (see Fig. 16) is provided to enable thetruckman to startthe stack conveyor motor 5| independently of thevarious control switches should the system stop from under voltagerelease or other causes after a basket I passes the switch I65 with--astack tion during said lifting and discharging operations.

2. In a mechanism for lifting each successive uppermost box from the topof a rising stack of boxes and transferring each such box out of thepath of said rising stack, the combination of a rotary member rotatableon a horizontal axis and positioned for frictional engagement with oneside of said uppermost box; power means for driving said rotary memberat a peripheral speed greater than the rate of movement of said stack; abox engaging shoe adapted to engage the side of said box opposite theside engaged by said rotary member; guide means determining the path oftravel of said shoe, said path extending across the path of said risingstack and over the top of said rotary member; and power means for movingsaid shoe along said path, said rotary member and said shoe coacting tolift said uppermost box from said stack, said shoe operating todischarge said box over the top of said rotary member.

3. In a mechanism for lifting each successive uppermost box from the topof a rising stack of boxes and transferring each such box out of thepath of said rising stack, the combination of, a rotary member rotatableon a horizontal axis and positioned for frictional engagement with oneside of said uppermost .box; power means for driving-said rotary memberata peripheral speed greater than the rate of movement of said stack; abox engaging shoe adapted to engage the side of said box opposite theside engaged by said rotary member; guide means determining the path oftravel of said shoe, said path extending across the path of said risingstack and over the top of said rotary member; power means for movingsaid shoe along said path, said rotary engaging means being .driven atafaster rate of speed than the rate of travel of said elevator,

each of said successive uppermost boxes being member and said shoecoacting to lift said uppermost box from said stack and said shoedischarging said box over the top of said rotary member; and powertransmitting means associated with said power means to vary the velocityof said shoe, said velocity being decreased as said box is lifted fromsaid stack by said rotary member and said shoe, and increased as saidbox is discharged by said shoe.

4. A combination as in claim 3 in which the velocity of said shoe duringthe lifting of said box from said stack is less than the/velocity of theperiphery of said rotary member and greater than the velocity of saidrising stack.

5. In a machine for elevating a stack of filled boxes, the combinationof: a substantially vertical stack elevator; a horizontal conveyor fordelivering stacks of boxes to said elevator; means for verticallyaligning the boxes of a stack transversely of the direction of travel ofsaid stack on said conveyor; and control means-responsive to boxes ofsaid stack which are misaligned in relation to said stack in thedirection of travel of said stack on said conveyor to prevent saidelevator from starting.

6. In a machine for elevating a stack of filled boxes, the combinationof a substantially vertical stack elevator; a horizontal conveyor fordelivering stack of boxes to said elevator; a vertical drum on oppositesides of said conveyor, said drums aligning the boxes of said stacktransversely of the direction of travel of said stack; and power meansfor driving said drums in opposite directions, the inner faces of saiddrums moving in the same direction as the dimotion of travel of saidstack.

7. A combination as in claim 6 in which said drums are driven from saidconveyor at a peripheral speed equal to the rate of travel of saidconveyor.

8. In a machine for unstacking stacks of boxes, the latter having sidesand bottoms secured to outer edges of the heads thereof, the combinationof: an elevator for continuously raising said stack; a pair of spacedbox clamping elements at the upper end of said elevator, said elementsbeing positioned to receive and clamp each successive uppermost box ofsaid stack therebetween during vertical movement of said stack, saidelements engaging said box on opposite sides thereof and power means formoving said box clamping elements upward, away from said stack andtransversely, out of the path of said rising stack as the lattercontinues to rise and while holding said box in substantially uprightcondition, the speed of said upward movement of said clamping membersbeing greater than the speed of said continuously rising stack to enablesaid members to lift said uppermost box free from the next lower box ofsaid stack prior to moving said box out of the path of said risingstack.

9. In a mechanism for lifting each successive uppermost box from the topof a rising stack of boxes and transferring each such box out of thepath of said rising stack, the combination of: a rotary member rotatableon a horizontal axis and positioned for frictional engagement with oneside of said uppermost box; power means for driving said rotary memberat a peripheral speed greater than the rate of movement of said stack; abox engaging shoe adapted to engage the side of said box opposite theside engaged by said rotary member; and means for moving said shoeagainst said opposite side of said box to clamp said box against saidrotary member and lift said box upwardly from the balance of said stackto separate said box from said stack.

10. In a mechanism for lifting each successive uppermost box from thetop of a rising stack of boxes and transferring each such box out of thepath of said rising stack, the combination of a rotary member rotatableon a horizontal axis and positioned for frictional engagement with oneside of said uppermost box; power means for driving said rotary memberat a peripheral speed greater than the rate of movement of said stack; abox engaging shoe adapted to engage the side of said box opposite theside engaged by said rotary member; and means for moving said shoeagainst said opposite side of said box to clamp said box against saidrotary member and lift said box upwardly from the balance of said stackto separate said box from said stack, said last mentioned means causingsaid shoe to travel when engaging said box as aforesaid, co-ordinatelywith said rotary member so as to retain said box in substantiallyupright condition while separating said box from said stack.

11. In a mechanism for lifting each successive uppermost box from thetop of a rising stack of boxes and transferring eachsuch box out of thepath of said rising stack, the combination of: a rotary member rotatableon a horizontal axis and positioned for frictional engagement with oneside of said uppermost box; power means for driving said rotary memberat a peripheral speed greater than the rate of movement of said stack; abox engaging shoe adapted to engage the side of said box opposite theside engaged by said rotary member; and means for moving said shoeagainst said opposite side of said box to clamp said box against saidrotary member and lift said box upwardly from the balance of said stackto separate said box from said stack, said last mentioned means causingsaid shoe to travel when engaging said box as aforesaid, co-ordinatelywith said rotary member so as to retain said box in substantiallyupright condition while separating said box from said stack and whilethus maintaining said box in an upright condition, conveying said box ina path which follows and passes over the periphery of said rotarymember.

12. In a machine for elevating a stack of boxes, the combination of: astack elevator; power means for driving said stack elevator; ahorizontal conveyor for delivering stacks of boxes to said elevator; andcontrol means responsive to a box out of vertical alignment with theremainder of a stack being moved into position to be elevated by saidstack elevator, said control means rendering said stack elevatorinoperative prior to elevation of said stack until said box is alignedwith the remainder of said stack.

, 13. A combination as in claim 12 in which said control means isco-extensive with the height of said stack.

14. In an elevating apparatus for a stack of articles or the like, thecombination of: horizontal conveyor means for conveying a series ofstacks to a given location; an elevator for elevating a stack after thelatter has been delivered to said location; and rotary aligning elementsdisposed at opposite sides of a stack arriving at said location, saidaligning elements being spaced a distance substantially equal to thelength of said articles so as to align said articles with the-remainderof said stack as said stack is delivered to said location.

15. A combination as in claim 14 in which each of said rotary aligningelements comprises a cylindrical drum rotatable about a vertical axis.

16. A combination as in claim 14 in which power means is provided fordriving said rotary aligning elements.

17. A combination as in claim 14 in which said rotary aligning elementsare positioned to constitut vertical guides for said stack while thelatter is being elevated by said elevator.

18. In an apparatus for handling boxes, the combination of: rotary meansfor frictionally engaging a side of a box when the latter is pressedthere-against; shoe means adapted to engage the opposite side of saidbox; and means for co-ordinately rotating said rotary means and causingsaid shoe means to travel into engagement with the box as aforesaid andalong a path so as to grip said box between said rotary means and saidshoe means to lift said box while maintaining sa d box substantiallyupright.

19. In an apparatus for handling boxes, the combination of: rotary meansfor frictionally engaging a side of a box when the latter is pressedthere-against; shoe means adapted to engage the opposite side of saidbox; and means for coordinately rotating said rotary means and causingsaid shoe means to travel into engagement with the box as aforesaid andalong a path so as to grip said box between said rotary means and saidshoe means and lift said box under the impulse of said shoe means alonga path extending over said rotary means, said rotary means and said shoemeans co-operating to maintain said box in upright position duringmovement of said box along said path,

20. In an apparatus for handling boxes, the combination of: 'rotarymeans for frictionally the opposite side of said box; .power means forco-ordinately driving said rotary means and said shoe means to causesaid box to be clamped therebetween and lifted thereby, said power 7said box, said shoe .meansmaintainingssaid box in engagement with saidmemberrand then pro means causing said shoe means to travel at such arate that after said box has been lifted a certain distance said shoemeans propels said box to cause the latter to skid upon and over saidrotary member and thus produce a pressure between said shoe means andsaid box, said pressure preventing the side of the box engaged by saidshoe means from dropping.

21. In a box handling apparatus, the combination of: means forming africtional surface adapted to support a given side of a box byengagement of the lower edge of said side with said surface; frictionshoe means for engaging the opposite side of said box; and means forcausing said shoe means to move against said opposite side in adirection to force the first mentioned side edge of said box againstsaid frictional surface, skid said box thereacross, and sustain theweight of said box during said skidding by the frictional engagementtherewith of said first mentioned means and said shoe means.

-22. In a stack handling apparatus, the combination of: a stackelevator; a conveyor for delivering a stack of boxes into position to beelevated by said elevator; stop means for arresting movement of saidstack in position to be elevated by said elevator; elevator controlmeans at opposite sides of said delivery conveyor, said control meansbeing moved to operative position during passage of a stacktherebetween, the distance between said stop means and said controlmeans being slightly greater than the width of the boxes comprising saidstack; and means responsive to said control means to disable saidelevator when said control means is retained in said operative positionby misaligned boxes of said stack upon the arrival of said stack inposition to be elevated.

23. A combination as in claim 22, in which said elevator control meanscomprises a pair of gates coextensive with the height of said stack.

24. In a stack handling apparatus, the combination of z a stackelevator; a conveyor for delivering a stack of boxes into position to beelevated by said elevator; stop means for arresting movement of saidstack in position to be elevated by said elevator; and elevator controlmeans responsive to misalignment of the boxes in said stack in adirection away from said stop means to prevent the elevation of saidstack by said elevator.

25. In a box handling apparatus, the combination of: a rotary frictionmember; means for rotating said member; means for delivering a box to aposition alongside said member; shoe means; and meansformoving'said shoemeans J along a path to cause: saidshoe means 'to engage and hold saidbox againstv said m'ember and operate "with said member inifrictionallylifting peliing said'box.over said 'inember whilemainsubstantiallyupright positaining said box in tion.

26. In a box handling apparatus, the combi nation of: a rotary frictionmember; means for rotating said member; means for delivering a' along apath to cause said shoe means to engage and hold said box against saidrotary friction member and co-operate with said member in frictionallylifting said box and then moving said box over said rotary frictionmember, said moving means causing said shoe to travel at a given rate ofspeed when first engaging said box and at a substantially acceleratedrate of speed when moving said box over said member, while maintainingsaid box in substantially upright position.

27. In a box handling apparatus, the combination of: a rotary frictionmember; means for rotating said member; means for delivering a box to aposition alongside said member; shoe means; and means for moving saidshoe means along a path to cause said shoe means to engage and hold saidbox against said member and cooperate with said member in frictionallylifting said box, said shoe means maintaining said box in engagementwith said member and then propelling said box over said member whilemaintaining said box in substantially upright position, said shoe movingmeans causing said shoe to travel, when first binding said box againstsaid member, at a rate which is slower than the peripheral speed of saidrotary friction member.

28. In a machine for unstacking astack of boxes, the combination of: anelevator for receiving and continuously elevating a stack of boxes withthe boxes in said stack mainly supported by those boxes in said stackdisposed therebeneath; and power driven means positioned to operate onthe upper end of said stack in timed relation with the elevation of saidstack, said means gripping each of the uppermost boxes in said stack inthe planes of the ends of said box, lifting said box upwardly from thebalance of said stack, and shifting said box, while retaining the samein upright position, out of the path of said stack.

GEORGE P. MARSDEN. FRED S'IEBLER.

